Gear synchronizer assembly for power transmission

Abstract

In a gear synchronizer assembly of the well-known type, a clutch sleeve is formed at its inner periphery with at least one first internal radial projection of large width and a pair of circumferentially spaced second internal radial projections of small width arranged at opposite sides of the first internal radial projection, a synchronizer ring being formed thereon with a pair of raised portions to be engaged with the first internal radial projection and another pair of raised portions to be engaged with the second internal radial projections. A thrust mechanism comprising a radially contractible annular spring is supported in place by engagement with the inner circumference of a cylindrical hub portion of a hub member fixed to a transmission shaft. The annular spring has an axial leg extending therefrom toward the first internal radial projection, and having a radial projection which is arranged to be engaged with the first internal radial projection in shifting operation of the clutch sleeve toward a spline piece integral with a change-speed gear and arranged to abut against and urge the synchronizer ring toward the spline piece upon engagement with the first internal radial projection.

What is claimed is: 
     
       1. In a gear synchronizer assembly comprising a gear member rotatable on a transmission shaft, a spline piece mounted on said gear member for rotation therewith and being formed at one side thereof with a conical portion and thereon with external spline teeth, a synchronizer ring mounted on the conical portion of said spline piece for frictional engagement therewith, a hub member fixedly mounted on said shaft for rotation therewith and having a cylindrical hub portion encircling said synchronizer ring and formed thereon with external spline teeth, a clutch sleeve encircling the cylindrical hub portion of said hub member and having internal spline teeth in continual engagement with the external spline teeth of said hub member, said clutch sleeve being axially shiftable toward and away from said gear member to be engaged at the internal spline teeth thereof with the external spline teeth of said spline piece, and thrust means for thrusting said synchronizer ring toward said spline piece in shifting operation of said clutch sleeve toward said gear member to effect frictional engagement of said synchronizer ring with said spline piece, the improvement wherein said clutch sleeve is formed at an inner periphery with a first internal radial projection of large circumferential width and a pair of circumferentially spaced second internal radial projections of small circumferential width arranged at opposite sides of the first internal radial projection, the first and second internal radial projections each being formed at one side thereof with a pair of chamfers and being axially movable in corresponding axial grooves formed in the cylindrical hub portion of said hub member, wherein said synchronizer ring is formed thereon with a pair of raised portions which are arranged to be engaged with the first internal radial projection, said synchronizer ring being further formed thereon with another pair of raised portions which are arranged to be engaged with the second internal radial projections, and wherein said thrust means comprises a radially contractible annular resilient member supported in place by engagement with an inner circumference of the cylindrical hub portion of said hub member, said resilient member having an axial leg extending therefrom toward the first internal radial projection of said clutch sleeve and having a radial projection arranged to be brought into engagement with the first internal radial projection of said clutch sleeve in shifting operation of said clutch sleeve toward said gear member and being arranged to abut against and urge said synchronizer ring toward said spline piece upon engagement with the first internal radial projection of said clutch sleeve, the axial leg of said resilient member being arranged to be compressed radially inwardly by engagement with the first internal radial projection of said clutch sleeve.   
     
     
       2. A gear synchronizer assembly according to claim 1, wherein the first internal radial projection of said clutch sleeve is formed at an inner end with a tapered surface engageable with an innner shoulder of the axial leg of said annular resilient member. 
     
     
       3. A gear synchronizer assembly according to claim 1, wherein three equi-spaced first internal radial projections are formed at the inner periphery of said clutch sleeve, and wherein said radially contractible annular resilient member includes a C-letter shaped ring portion which is formed at oppposite ends thereof with a pair of circumferentially spaced axial legs and at an intermediate portion thereof with an axial leg, eabh of said axial legs extending from said ring portion toward a corresponding first internal radial projection of said clutch sleeve, and each of said axial legs having a radial projection arranged to be brought into engagement with the corresoonding first internal radial projection of said clutch sleeve. 
     
     
       4. In a gear synchronizer assembly comprising a gear member rotatable on a transmission shaft, a spline piece mounted on said gear member for rotation therewith and being formed at one side thereof with a conical portion and thereon with external spline teeth, a synchronizer ring mounted on the conical portion of said spline piece for frictional engagement therewith, a hub member fixedly mounted on said shaft rotation therewith and having a cylindrical hub portion encircling said synchronizer ring and formed thereon with external spline teeth, a clutch sleeve encircling the cylindrical hub portion of said hub member and having internal spline teeth in continual engagement with the external spline teeth of said hub member, said clutch sleeve being axially shiftable toward and away from said gear member to be engaged at the internal spline teeth thereof with the external spline teeth of said spline piece, and thrust means for thrusting said synchronizer ring toward said spline piece in shifting operation of said clutch sleeve toward said gear member to effect frictional engagement of said synchronizer ring with said spline piece, the improvement wherein said clutch sleeve is formed at an inner periphery with a first internal radial projection of large circumferential width and a pair of circumferentially spaced second internal radial projections of small circumferential width arranged at opposite sides of the first internal radial projection, the first and second internal radial projections each being formed at one side thereof with a pair of chamfers and being axially movable in corresponding axial grooves formed in the cylindrical hub portion of said hub member, wherein said synchronizer ring is formed thereon with a pair of raised portions which are arranged to be engaged with the first internal radial projection, said synchronizer ring being further formed thereon with another pair of raised portions which are arranged to be engaged with the second internal radial projections, and wherein said thrust means comprises a radially contractible annular resilient member arranged in surrounding relationship with said synchronizer ring and axially slidably supported in place by engagement with an inner circumference of the cylindrical hub portion of said hub member, said resilient member having an axial leg extending therefrom toward the first internal radial projection of said clutch sleeve and having a radial projection arranged to be brought into engagement with the first internal radial projection of said clutch sleeve in shifting operation of said clutch sleeve toward said gear member and being arranged between said hub member and said synchronizer ring to abut against and urge said synchronizer ring toward said spline piece upon engagement with the first internal radial projection of said clutch sleeve, the axial leg of said resilient member being arranged to be compressed radially inwardly by engagement with the first internal radial projection of said clutch sleeve.